The present invention relates to the tire service equipment industry and more particularly to an apparatus and method for testing and inspecting tires under high pressure. The invention finds its principal application in the field of tire retreading and repair and is useful in the inspection and testing of tire casings prior to retreading or repair and of finished tires after the retread or repair has been completed.
It is well known in the art that a tire may be inspected or tested for defects, such as ply separations and nail holes, or for quality control of finished, repaired or retreaded tires when fully or partially inflated. However, when a tire is inflated to high pressure, i.e. in excess of 50 p.s.i., defects may be more pronounced or more efficiently detected than when the tire is not inflated. Nevertheless, high pressure inspection and testing of tires is relatively uncommon because of the time required to mount the tire, inflate it and then remove the tire from the wheel after the inspection or test procedure has been completed. In addition, prior art equipment designed to facilitate high presure tire servicing has been relatively complex and expensive and has found only limited acceptance in the tire retreading and repair industry.
One common and troublesome defect found in used tires that would otherwise be suitable for retreading and repair is the difficulty associated with discovering and locating small air leaks, such as nailholes. A variety of non-destructive testing devices have been suggested in the art for solving this problem, including high voltage electronic discharge machines and several different forms of ultrasonic testing apparatus.
For the most part, the nail hole detection equipment of the prior art utilizes non-inflated tires. A few prior art devices have used inflated tires. In either case, however, the prior art equipment all suffers from the disadvantage that it is costly, complex equipment and oftentimes difficult to use.